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Main PCB Circuit Diagram 415
0 Connector for the power supply PCB
O-1: CR1, recording head on/off relay
(_) 3-terminal regulator which eliminates unstabilized components of the +9V source to
generate stabilized 5V source.
(_ Connector for the NCU
(_)-1: Power for the NCU
(_)-2: Signals to the telephone
(_)-3: Signals from the telephone
(_) Analog signal selectors
(_)-1: Selects either input signals from the handset or those from the MODEM.
(_)-2: Selects either RL1 or RL2 signals inputted from the communications network.
(_)-3: Selects sound signals (e.g., alarm beeps, key clicks and ringer sounds) gener-
ated by the FAX engine, hands-free monitor signals, or voice playback signals.
(_ Analog signal selectors
(_)-1 Selects either signals gated by (_-2 or voice signals coming from the handset.
(_)-2 Selects either signals gated by (_-2 or voice playback signals.
(_-3 Selects either signals gated by (_)-2 or hands-free monitor signals.
(_) Amplifier circuit for signals outputted from the MODEM
(_) Analog front end IC which processes the analog I/O signals from/to the MODEM.
(_) Amplifier & shaper circuit for signals inputted from the communications network.
(_) Telephone circuit for transmitting signals.
III - 23